Issue 65

G. Hatti et alii, Frattura ed Integrità Strutturale, 65 (2023) 88-99; DOI: 10.3221/IGF-ESIS.65.07

fracture [33]. Fig. 5(b), 5(c) and 5(d) to depicts fractograph of Al7075-NLP-SiC hybrid-MMCs. River-like structures, cleavage facades, and voids with plenty of cavities and lower dimples after reinforcements have uneven tearing troughs, and less ductile failure can be observed throughout the images indicating brittle fracture [36-37]. and has a quasi- cleavage feature mode-cleavage feature mode. Materials with lower elongation values frequently exhibit quasi-cleavage fracture. Large SiC particles or broken Al-Si eutectic particles may be to blame for this. The form and size of the particles have a significant impact on the tensile properties, as is well known. The Al-Si eutectic particles in the 7075 alloy are big and elongated, making them more brittle and susceptible to cracking. Thus, the inter-dendritic cracking and silicon particle cracking dominate the fracture process in the 7075 alloy. While in composites, the dislocations accumulate close to the SiC particles, creating stress fields that in turn induce local fluctuations that eventually cause the SiC particles to shatter. It is significant to notice that SiC particles broke under tensile loading rather than debonded due to the strong link between the 7075 matrix and the SiC particles. The interfacial connection between the SiC particles and 7075 matrix is crucial in cases of tensile loading. When loading circumstances are present, it attempts to keep the SiC particles in the matrix if the interfacial bonding is strong. Because to the high interfacial bonding, however, as the load increases, the SiC particles fracture rather than debond. Hence, the nature of fracture in composites is brittle [36-37].

Figure 5: Fracture Analysis of Al7075-NLP-SiC hybrid-MMCs.

Wear test results Wear tests of prepared compositions were conducted with applied loads, sliding speeds, and sliding distances, and all the parameters are shown in Tab. 3.

94